In general, a radio frequency (RF) communication system performs communication according to a Frequency Division Duplexing (FDD) access scheme or a Time Division Duplexing (TDD) access scheme. The FDD access scheme divides and uses a total frequency band in an RF communication system into a frequency domain for uplink and a frequency domain for downlink. Meanwhile, the TDD access scheme divides a predetermined time interval into a time domain for uplink and a time domain for downlink, and uses a total frequency band in the respective time domains. Through this, according to the TDD access scheme, transmission efficiency may be relatively improved in an RF communication system, and a rate of a resource allotted to uplink and downlink may be easily controlled.
Accordingly, in the RF communication system supporting the TDD access scheme, as shown in FIG. 1, a communication terminal 100 may control a transmitting path for uplink and a receiving path for downlink to use the TDD access scheme. At this time, the transmitting path may be formed via a transmitter 110, a Radio Frequency High Power Amplifier (RFPA) 120, an isolator 130, a TDD Switch (SW) 140, a TDD filter 150, and a TDD Antenna 160. The receiving path may be formed via the TDD antenna 160, the TDD filter 150, the TDD SW 140, a Low Noise Amplifier (LNA) 170, and a receiver 180. Here, the TDD switch 140 may block physical connection between the transmitting path and the receiving path.